1. Field of the Invention
The subject invention relates to a method and system for rearranging documents within a logical group of a single stream or multiple streams of printed documents (frequently single to multi-page billing statements within a particular printing job). Small documents are paired with large documents for a logical group of documents that are mailed together. This arrangement (utilizing an appropriately designed sorting routine/algorithm) allows for greater inserting efficiencies and higher throughput of documents, thereby resulting in overall lower document preparation costs. More specifically, the operation of a mailing inserter is smoothed and made more efficient via utilization of large with small document combination optimization since the sortation algorithm alternates the order of documents with the smallest sheet count documents followed by the largest sheet count documents in order to optimize the throughput of an associated mail inserter based on the maximum speed that documents can be collated and accumulated in an associated collator/accumulator.
2. Description of Related Art
In the past, postal regulations have stipulated that in order to obtain the maximum discount for postage under a manifest mail agreement, that the documents must meet stringent requirements as outlined in the “Domestic Mail Manual” (DMM). Included in the DMM are requirements for the sorting of a group of documents destined to be mailed (a “mailing”) by the United States Postal Service (USPS). In order for a bulk mailer to obtain the maximum discount, the mail must be sorted by the destination zip code, carrier route, and walk route order. Included in the requirement is that the sort order of the documents must be maintained throughout the mailing. Consequently, when the documents were placed in a mail tray for submission to the USPS, the sort order was to be maintained within the tray (see FIG. 1-PRIOR ART).
In a printing/mailing facility that prints and mails documents in accordance with DMM standards, in order to obtain postal discounts, the documents are typically printed on a continuous form printer on a continuous web of printable material. An example of this type of printer is the IBM InfoPrint 1332. While sorting can be performed after documents have been produced using a mail sorting machine, printing and inserting documents in the correct sort order offers business and process benefits.
Subsequent to printing, the continuous form paper is placed on a mail inserting machine (e.g., a Bowe Bell+Howell 3000) that cuts the paper, accumulates the cut paper into collated documents, and then inserts the accumulated documents into an envelope. Since the document may contain one to a plurality of sheets (with a total odd or even sheet count), the time it takes to accumulate the paper for a document varies in proportion to the number of sheets per document. While the document is accumulating, conventional inserters continue to cycle, thereby wasting time. This causes the inserters to be less efficient than possible since the inserter cycles at a speed higher than documents can be delivered to the inserter due to the varying sheet count. If there are a large number of low sheet count documents, the inserter may not be able to cycle fast enough to accept all of the documents, thus causing the document accumulator to be less efficient than possible.
On inserters with “dynamic motion control” (see U.S. Pat. No. 5,724,791, which is herein incorporated by reference) the mail inserter cycles at the optimal speed based on the number of sheets being accumulated in the document. A dynamic motion control system is utilized for decreasing wear and tear or mechanical degradation on an envelope inserting apparatus, thereby increasing the life of the envelope inserting apparatus. The envelope inserting apparatus or transferring means (transferring in the sense of taking the incoming documents and inserts from the moving means or folder, assembling the mail items, and transferring the mail items to any further processing equipment) is coupled to means for printing document packets which are moved to the inserting apparatus at variable intervals. More specifically, the dynamic motion control system is employed with an inserter machine that receives packets of documents having possibly different numbers of pages within each packet and each packet is inserted into a mailing envelope. The dynamic motion control system efficiently coordinates the operational speed of the inserter with the period of time required to print the document pages within each incoming packet (larger sheet count documents take more time than smaller sheet count documents to assemble and are more sensitive to being damaged during the envelope insertion process if moved too quickly), thereby both speeding up the insertion process and minimizing repairs to the inserter machine.
Large and Small Sheet Count Document Combinations: A typical document handling/insertion system is depicted in FIG. 2 in which rolled web paper, having the desired documents printed upon it, is unwound, passed through a slitter, a cutter (position A in FIG. 2), a collator/accumulator (position B in FIG. 2), a folder (position C in FIG. 2), into a mail inserter, and finally into a receiving envelope (position D in FIG. 2). Because of the previous goal of maintaining the final postal sort sequence, when documents are produced on inserters the cycle speed of the inserter is not optimal for all document sets of varying sheet count. A small sheet count document requires little time to accumulate in the collator (position B in FIG. 2) out of the cutter (position A in FIG. 2) while large sheet count documents require relatively more time to accumulate. The inserter may be between cycles for small sheet count documents, while the inserter may cycle one or more times waiting for a large sheet count document, thereby wasting time and money.
Even and Odd Sheet Count Document Alignment: Inserters using continuous form cutters (position A in FIG. 2) can utilize a double sheet cutter where two sheets are delivered in a single cut cycle when they are side-by-side on the web and part of the same document, a 100% throughput improvement over single sheet cut cycles. Using this type of cutter, odd sheet count documents always require the same number of cut cycles: ((N−1)÷2)+1 (where N is the number of sheets in a document) (FIG. 3). But even sheet count documents require either (N÷2) or (N÷2)+1 cut cycles, depending on whether all the sheets are aligned side-by-side or not (FIG. 4).
If no consideration is made for even sheet count statement alignment, then up to half of them will require (N÷2) cut cycles and the rest (N÷2)+1 cut cycles. This difference can have a significant impact on throughput. For example, a job of 10,000 documents where half are two sheets and half are three sheets would require 15,000 cut cycles if all two sheet documents were aligned side-by-side. Without side by side alignment, on average 17,500 cut cycles are required, a 16.7% increase.
Additionally, it is noted that USPTO Publication No. 20060080122 (Klopsch, et al., Multi-print Stream Processing Module Optimizer for Document Processing) describes a document processing patent that optimizes the order of multiple print streams of documents comprising documents that are destined for processing on an inserter. The result is increased throughput on the inserter since the multiple cutters are preparing the documents concurrently. The subject invention differs in a major and critical way from the invention described in this publication since the subject optimization is to a single print stream, whereby each print stream is optimized individually and not across print streams. In addition, the sort algorithms employed in the subject invention are not like those in the Klopsch et al. publication in that the print streams are optimized without regard for individual mail unit rules since those rules no longer apply.